bclexus

Lexus will completely flush the transmission and it will have 100% new fluid all in one event. However, beware of flushing a transmission. It can cause more harm than good by stirring up debris and clogging up the valve body. I recommend a number of drain-and-fills. The reason Lexus (or any dealership's service department) doesn't normally do drain-and-fills is because it would require the customer to come back numerous times to complete the process.

The 'drain and fill' (D & F) is a DIY method done over a period of time - anywhere from each individual D & F taking place a few hours apart (with the vehicle purposely driven ~100+ miles to mix the old and new fluid and dissolve some varnish/trash), to months apart (where the vehicle is driven thousands of miles) between D & Fs. When doing D & Fs the idea is to get the fluid replaced to a percentage of 75% or more over a period of time where the new fluid mixes with the old...and each subsequent D & F becomes a fresher blend of the new and old fluid, with the goal being that the old fluid becomes a minor percentage of the fluid mix.

Doing D & Fs I would recommend driving the car ~100 miles (but a minimum of 20 miles in stop-n-go traffic with a few high rpm shifts) between D & Fs to thoroughly mix the fresh ATF with the old ATF and dissolve some tarnish and float some debris. Also, I think it is always best to use the same exact ATF that the car maker originally installed in the transmission.

If you do decide to do 'Drain & Fills' you'll need to do at least a few of them to get where you only have ¼ of old dirty fluid remaining. Most transmissions will drain 3.5 - 4 quarts of ATF when doing D&Fs, some as little at 2.5 quarts. I don't recall ever hearing of one that drained less than 2 quarts.

The A760E 6-speed transmission has a fluid capacity of 11.6 U.S. Quarts. I do not know the fluid capacity offhand of the A760H (AWD) transmission or the 8-speed transmission, however those transmission's capacities will likely be within a quart of the A760E 6-speed transmission. Most automatic transmissions will usually drain about 4 to 4¾ quarts of fluid. For example, if you are able to drain 4.65 quarts of the transmission's 11.6 quart total capacity that would provide the 1st D & F to replace 40% of the entire fluid, but leave 60% old dirty fluid remaining. And the 2nd D & F leaves 36% old dirty fluid remaining, the 3rd D & F leaves 22% old dirty fluid remaining and the 4th D & F leaves 13% old dirty fluid remaining. The math is 60% x .60 = 36% x .60 = 22% x .60 = 13% and so on, and so forth. Of course, if the total transmission fluid capacity is greater than ~11.6 quarts or if the drain amount is less than ~4.65 quarts, then the number of 'Drain & Fills' to accomplish a reasonable fluid replacement increases. (See the attached Excel spreadsheet for a quick and easy way to determine what percentage of old dirty fluid remains based on how many drain-and-fills are done.)

I think there is a additional benefit to doing 'Drain and Fills' in lieu of flushing, especially if the transmission fluid is really old or has been overheated or subjected to extreme use. Flushing can often cause (yes - 'cause') transmission failures where there was no indication of failure before. The reason this can sometimes happen is because a flushing will fill the transmission with 100% new fluid that can dissolve old fluid varnish and trapped dirt/slush within the transmission, which in-turn can cause bits of varnish and trash to clog up the tiny orifices and ports within the transmission, causing failure.

► See the attachment below for a nice Excel spreadsheet 'ATF Drain and Fill Calculator' that can be changed (in Excel Cells C5 & C6) to reflect any vehicle's transmission total capacity and the fluid drain amount so you can easily determine the number of Drain-and-Fills you'll need to accomplish.

JeffKeryk

I will be doing a spill and fill service on our 2013 F Sport before too long; probably March...
In addition to BC's good post, I believe it is pretty important to do a fluid level check, which is performed on a level stance, trans fluid temperature at 104 F (off the top of my head) and the fluid slowly draining from the straw.

In my case, I plan draining and filling with the same amount, running engine for maybe 20 seconds; then repeat for a total of 3 times.
After the 3rd iteration, I will perform the fluid level check. I am using an OBD2 Bluetooth module and app.
The goal is for the pump to cycle the pan volume to transmission body and replace with dirty fluid.

On a RWD drive car, this will take maybe 9 to 11 quarts of fluid, dunno for sure as I have never done this.
I like the Idemitsu WS equivalent, others like the factory WS fluid. Up to you...
I certainly do not believe in lifetime fluids. In fact, you might make a case that an early transmission service is beneficial as transmission break in can result in excess metal...
I will post my results and ask others to offer their thoughts, because I learn from all of you.

UDel

Drain and fill is basically like changing your oil. You unscrew the bolt under the car, let everything you can drain out through gravity, put the bolt back on and refill back with new fluid with what came out,. When it comes to transmissions a large amount of fluid still stays in the torque converter and maybe other areas so you don't get nearly as much old fluid out as you would a oil change/flush so you have to do a drain and fill 3 times or so to pretty much replace all the old fluid though just adding new fluid once does make a pretty big difference especially when this is supposed to be lifetime fluid.

With a flush they are using a machine to put pressure in the transmission and suck out pretty much all the old fluid at once and replacing it with new fluid. Problem is this method can dislodge sludge/particles that were setting in a harmless area and cause them to move around and plug up partially or fully passages/chambers that are critical and need full lubrication so even though you have new fluid, the fluid is not getting to some critical areas now and it can cause major transmission issues and even failures very quickly.

thallium

Do you recall where you got the 104 F? On my Camry the temp range was 104-113 F. Regarding the GS I've seen that and also 105-116 F. I think the latter is correct but don't remember where I read it.

Also, do you mind sharing what OBD2 app you use and how you're getting the trans temp? Is the PID available in there or did you have to pay extra or did you create it? When I did this on my Camry I used OBD Fusion on iOS with a bluetooth PLX Kiwi3 device. The trans temp was not available but I found a custom PID someone on a Tacoma forum created that worked on my Camry. I compared it's temp with the OBD2 port jumper method and and they were within a degree or so of each other. Later I bought a model specific upgrade in the OBD Fusion software and it had several trans temps but they did not seem to work.

richard203

iTrader: (1)

you can buy TechStream software on ebay its lexus and Toyota scanner

AJLex19

I have 56k miles on my 4GS and i wasn't even contemplating changing the tranny fluid at this point - i'm actually more concerned about the front differential fluid on my AWD since I never had that changed (did the rear differential oil at 47k miles). I've looked at a lot of 4GS cars for sale and I rarely see any Carfax reports showing the tranny fluid being changed at 60k.

Just personal opinion: you should change the tranny fluid if you feel like it would provide a benefit based on the type of driving that you do and how long you intend to keep the car. Even though I drive in a lot of stop and go traffic I likely won't change it. Had my 2GS until 125k miles - never changing the transmission fluid and never had any transmission issues (had more issues with the OEM exhaust components)...but if i had kept it past that 125k mileage point, i probably would have had the tranny fluid checked/changed.

Thats just my personal experience and 2 cents but definitely let us know if you get it done, if the car feels better/different.

richard203

iTrader: (1)

ya I changed most of those fluid because im keeping the car for life!! LOL if I sale it now I will lose a lot of money so might as well keep it and give it to my son or daughter when they grow up. LOL

thallium

Probably because most of the original buyers sell/trade them before 60k and get something else. They don't care. BTW, the car I bought (RWD) had the diff oil changed at 30k and again at 60k.

mdr2001

Here is a link to DIY Dan's 'how to' video. It has the specs of 102-120F at 6:05 time. This should be all you need to get a full scope of the work and process involved.

JeffKeryk

I bought Rated high on Amazon; like $22.
Tried it out on my old Tundra.
Loaded Torque Lite and connected via Bluetooth.

Then loaded ELMScan Demo for Toyota; I was able to read transmission fluid temperature, which was my goal.
I will probably get the $5 version cuz I'm a big spender.

CottageChz

At 90k miles I took the car to my Lexus dealer and said I wanted the transmission fluid changed. They said, "We advise against flushes." I said, "Ok, good, because I don't want you to do a flush." Have read too many horror stories about flushes and that's not what I wanted. I asked them what they did in the process, and it was a simple drain and fill. They did not replace the filter. I asked them if they could replace the filter at my request, and they said, "No, we won't do that." I would have liked for them to replace the filter, but whatever, they wouldn't do it. Transmission fluid change is a service that I don't feel comfortable doing myself, so I let them do what they would. They quoted me between $200-300 for the job, can't remember for certain, but only ended up billing me like $120 (pleasant surprise).

Someone on the forum said that one of the most important things you get out of a flush is the new detergents in new fluid (I believe I am remembering this accurately), and even though with a simple drain and fill you don't replace 100% of the fluid, you replace enough for the new detergents to do their job cleaning and lubricating the transmission parts. He seemed to know what he was talking about, so I hope he is correct haha! Anyway, I feel better doing SOMETHING to the transmission and its "lifetime" fluid than doing nothing. I plan to have this service done again at some point, probably when I approach 140k miles.

Just my experience, thought I'd let you know.

2013lx570

fast forward to 7:40 of the video.

JeffKeryk

Can you please review your invoice and post the number of quarts of fluid you were charged for?
This will give me a clue as to how many iterations they performed. Most likely 1.
Thanks in advance.

Cwang

By the sound of it they couldn't be bothered dropping the pan to access the filter. I hope they haven't charged you for one!

temptingin

I've been reading on this three weeks ago my mechanic diagnosed it with trans mission needs to be changed, he suggested I get a another car.
Before it was only idle high on freeway. I realized that I was low on engine oil don't know if it has anything to do with it but now the it has since stopped I'm about to have him change the fluid.
BTW the computer said Trans is slipping!